diff options
Diffstat (limited to 'fs/buffer.c')
-rw-r--r-- | fs/buffer.c | 161 |
1 files changed, 125 insertions, 36 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index a2fd743d97cb..aed297739eb0 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -199,13 +199,13 @@ __find_get_block_slow(struct block_device *bdev, sector_t block) head = page_buffers(page); bh = head; do { - if (bh->b_blocknr == block) { + if (!buffer_mapped(bh)) + all_mapped = 0; + else if (bh->b_blocknr == block) { ret = bh; get_bh(bh); goto out_unlock; } - if (!buffer_mapped(bh)) - all_mapped = 0; bh = bh->b_this_page; } while (bh != head); @@ -290,7 +290,7 @@ static void free_more_memory(void) &zone); if (zone) try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0, - GFP_NOFS); + GFP_NOFS, NULL); } } @@ -360,7 +360,7 @@ still_busy: * Completion handler for block_write_full_page() - pages which are unlocked * during I/O, and which have PageWriteback cleared upon I/O completion. */ -static void end_buffer_async_write(struct buffer_head *bh, int uptodate) +void end_buffer_async_write(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; unsigned long flags; @@ -438,11 +438,17 @@ static void mark_buffer_async_read(struct buffer_head *bh) set_buffer_async_read(bh); } -void mark_buffer_async_write(struct buffer_head *bh) +void mark_buffer_async_write_endio(struct buffer_head *bh, + bh_end_io_t *handler) { - bh->b_end_io = end_buffer_async_write; + bh->b_end_io = handler; set_buffer_async_write(bh); } + +void mark_buffer_async_write(struct buffer_head *bh) +{ + mark_buffer_async_write_endio(bh, end_buffer_async_write); +} EXPORT_SYMBOL(mark_buffer_async_write); @@ -547,6 +553,46 @@ repeat: return err; } +void do_thaw_all(struct work_struct *work) +{ + struct super_block *sb; + char b[BDEVNAME_SIZE]; + + spin_lock(&sb_lock); +restart: + list_for_each_entry(sb, &super_blocks, s_list) { + sb->s_count++; + spin_unlock(&sb_lock); + down_read(&sb->s_umount); + while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb)) + printk(KERN_WARNING "Emergency Thaw on %s\n", + bdevname(sb->s_bdev, b)); + up_read(&sb->s_umount); + spin_lock(&sb_lock); + if (__put_super_and_need_restart(sb)) + goto restart; + } + spin_unlock(&sb_lock); + kfree(work); + printk(KERN_WARNING "Emergency Thaw complete\n"); +} + +/** + * emergency_thaw_all -- forcibly thaw every frozen filesystem + * + * Used for emergency unfreeze of all filesystems via SysRq + */ +void emergency_thaw_all(void) +{ + struct work_struct *work; + + work = kmalloc(sizeof(*work), GFP_ATOMIC); + if (work) { + INIT_WORK(work, do_thaw_all); + schedule_work(work); + } +} + /** * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers * @mapping: the mapping which wants those buffers written @@ -621,14 +667,7 @@ static void __set_page_dirty(struct page *page, spin_lock_irq(&mapping->tree_lock); if (page->mapping) { /* Race with truncate? */ WARN_ON_ONCE(warn && !PageUptodate(page)); - - if (mapping_cap_account_dirty(mapping)) { - __inc_zone_page_state(page, NR_FILE_DIRTY); - __inc_bdi_stat(mapping->backing_dev_info, - BDI_RECLAIMABLE); - task_dirty_inc(current); - task_io_account_write(PAGE_CACHE_SIZE); - } + account_page_dirtied(page, mapping); radix_tree_tag_set(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); } @@ -711,7 +750,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) { struct buffer_head *bh; struct list_head tmp; - struct address_space *mapping; + struct address_space *mapping, *prev_mapping = NULL; int err = 0, err2; INIT_LIST_HEAD(&tmp); @@ -736,7 +775,18 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) * contents - it is a noop if I/O is still in * flight on potentially older contents. */ - ll_rw_block(SWRITE_SYNC, 1, &bh); + ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh); + + /* + * Kick off IO for the previous mapping. Note + * that we will not run the very last mapping, + * wait_on_buffer() will do that for us + * through sync_buffer(). + */ + if (prev_mapping && prev_mapping != mapping) + blk_run_address_space(prev_mapping); + prev_mapping = mapping; + brelse(bh); spin_lock(lock); } @@ -1559,9 +1609,20 @@ EXPORT_SYMBOL(unmap_underlying_metadata); * locked buffer. This only can happen if someone has written the buffer * directly, with submit_bh(). At the address_space level PageWriteback * prevents this contention from occurring. + * + * If block_write_full_page() is called with wbc->sync_mode == + * WB_SYNC_ALL, the writes are posted using WRITE_SYNC_PLUG; this + * causes the writes to be flagged as synchronous writes, but the + * block device queue will NOT be unplugged, since usually many pages + * will be pushed to the out before the higher-level caller actually + * waits for the writes to be completed. The various wait functions, + * such as wait_on_writeback_range() will ultimately call sync_page() + * which will ultimately call blk_run_backing_dev(), which will end up + * unplugging the device queue. */ static int __block_write_full_page(struct inode *inode, struct page *page, - get_block_t *get_block, struct writeback_control *wbc) + get_block_t *get_block, struct writeback_control *wbc, + bh_end_io_t *handler) { int err; sector_t block; @@ -1569,6 +1630,8 @@ static int __block_write_full_page(struct inode *inode, struct page *page, struct buffer_head *bh, *head; const unsigned blocksize = 1 << inode->i_blkbits; int nr_underway = 0; + int write_op = (wbc->sync_mode == WB_SYNC_ALL ? + WRITE_SYNC_PLUG : WRITE); BUG_ON(!PageLocked(page)); @@ -1644,7 +1707,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, continue; } if (test_clear_buffer_dirty(bh)) { - mark_buffer_async_write(bh); + mark_buffer_async_write_endio(bh, handler); } else { unlock_buffer(bh); } @@ -1660,7 +1723,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, do { struct buffer_head *next = bh->b_this_page; if (buffer_async_write(bh)) { - submit_bh(WRITE, bh); + submit_bh(write_op, bh); nr_underway++; } bh = next; @@ -1697,7 +1760,7 @@ recover: if (buffer_mapped(bh) && buffer_dirty(bh) && !buffer_delay(bh)) { lock_buffer(bh); - mark_buffer_async_write(bh); + mark_buffer_async_write_endio(bh, handler); } else { /* * The buffer may have been set dirty during @@ -1714,7 +1777,7 @@ recover: struct buffer_head *next = bh->b_this_page; if (buffer_async_write(bh)) { clear_buffer_dirty(bh); - submit_bh(WRITE, bh); + submit_bh(write_op, bh); nr_underway++; } bh = next; @@ -2320,20 +2383,22 @@ int block_commit_write(struct page *page, unsigned from, unsigned to) * unlock the page. */ int -block_page_mkwrite(struct vm_area_struct *vma, struct page *page, +block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, get_block_t get_block) { + struct page *page = vmf->page; struct inode *inode = vma->vm_file->f_path.dentry->d_inode; unsigned long end; loff_t size; - int ret = -EINVAL; + int ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ lock_page(page); size = i_size_read(inode); if ((page->mapping != inode->i_mapping) || (page_offset(page) > size)) { /* page got truncated out from underneath us */ - goto out_unlock; + unlock_page(page); + goto out; } /* page is wholly or partially inside EOF */ @@ -2346,8 +2411,16 @@ block_page_mkwrite(struct vm_area_struct *vma, struct page *page, if (!ret) ret = block_commit_write(page, 0, end); -out_unlock: - unlock_page(page); + if (unlikely(ret)) { + unlock_page(page); + if (ret == -ENOMEM) + ret = VM_FAULT_OOM; + else /* -ENOSPC, -EIO, etc */ + ret = VM_FAULT_SIGBUS; + } else + ret = VM_FAULT_LOCKED; + +out: return ret; } @@ -2615,7 +2688,8 @@ int nobh_writepage(struct page *page, get_block_t *get_block, out: ret = mpage_writepage(page, get_block, wbc); if (ret == -EAGAIN) - ret = __block_write_full_page(inode, page, get_block, wbc); + ret = __block_write_full_page(inode, page, get_block, wbc, + end_buffer_async_write); return ret; } EXPORT_SYMBOL(nobh_writepage); @@ -2773,9 +2847,10 @@ out: /* * The generic ->writepage function for buffer-backed address_spaces + * this form passes in the end_io handler used to finish the IO. */ -int block_write_full_page(struct page *page, get_block_t *get_block, - struct writeback_control *wbc) +int block_write_full_page_endio(struct page *page, get_block_t *get_block, + struct writeback_control *wbc, bh_end_io_t *handler) { struct inode * const inode = page->mapping->host; loff_t i_size = i_size_read(inode); @@ -2784,7 +2859,8 @@ int block_write_full_page(struct page *page, get_block_t *get_block, /* Is the page fully inside i_size? */ if (page->index < end_index) - return __block_write_full_page(inode, page, get_block, wbc); + return __block_write_full_page(inode, page, get_block, wbc, + handler); /* Is the page fully outside i_size? (truncate in progress) */ offset = i_size & (PAGE_CACHE_SIZE-1); @@ -2807,9 +2883,20 @@ int block_write_full_page(struct page *page, get_block_t *get_block, * writes to that region are not written out to the file." */ zero_user_segment(page, offset, PAGE_CACHE_SIZE); - return __block_write_full_page(inode, page, get_block, wbc); + return __block_write_full_page(inode, page, get_block, wbc, handler); +} + +/* + * The generic ->writepage function for buffer-backed address_spaces + */ +int block_write_full_page(struct page *page, get_block_t *get_block, + struct writeback_control *wbc) +{ + return block_write_full_page_endio(page, get_block, wbc, + end_buffer_async_write); } + sector_t generic_block_bmap(struct address_space *mapping, sector_t block, get_block_t *get_block) { @@ -2922,12 +3009,13 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) for (i = 0; i < nr; i++) { struct buffer_head *bh = bhs[i]; - if (rw == SWRITE || rw == SWRITE_SYNC) + if (rw == SWRITE || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG) lock_buffer(bh); else if (!trylock_buffer(bh)) continue; - if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) { + if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC || + rw == SWRITE_SYNC_PLUG) { if (test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; get_bh(bh); @@ -2963,7 +3051,7 @@ int sync_dirty_buffer(struct buffer_head *bh) if (test_clear_buffer_dirty(bh)) { get_bh(bh); bh->b_end_io = end_buffer_write_sync; - ret = submit_bh(WRITE, bh); + ret = submit_bh(WRITE_SYNC, bh); wait_on_buffer(bh); if (buffer_eopnotsupp(bh)) { clear_buffer_eopnotsupp(bh); @@ -3277,11 +3365,12 @@ EXPORT_SYMBOL(block_read_full_page); EXPORT_SYMBOL(block_sync_page); EXPORT_SYMBOL(block_truncate_page); EXPORT_SYMBOL(block_write_full_page); +EXPORT_SYMBOL(block_write_full_page_endio); EXPORT_SYMBOL(cont_write_begin); EXPORT_SYMBOL(end_buffer_read_sync); EXPORT_SYMBOL(end_buffer_write_sync); +EXPORT_SYMBOL(end_buffer_async_write); EXPORT_SYMBOL(file_fsync); -EXPORT_SYMBOL(fsync_bdev); EXPORT_SYMBOL(generic_block_bmap); EXPORT_SYMBOL(generic_cont_expand_simple); EXPORT_SYMBOL(init_buffer); |